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1 /*
2  * GPL HEADER START
3  *
4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 only,
8  * as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * General Public License version 2 for more details (a copy is included
14  * in the LICENSE file that accompanied this code).
15  *
16  * You should have received a copy of the GNU General Public License
17  * version 2 along with this program; If not, see
18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19  *
20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21  * CA 95054 USA or visit www.sun.com if you need additional information or
22  * have any questions.
23  *
24  * GPL HEADER END
25  */
26 /*
27  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
28  * Use is subject to license terms.
29  *
30  * Copyright (c) 2011, 2013, Intel Corporation.
31  */
32 /*
33  * This file is part of Lustre, http://www.lustre.org/
34  * Lustre is a trademark of Sun Microsystems, Inc.
35  *
36  * lustre/fld/fld_request.c
37  *
38  * FLD (Fids Location Database)
39  *
40  * Author: Yury Umanets <umka@clusterfs.com>
41  */
42 
43 #define DEBUG_SUBSYSTEM S_FLD
44 
45 #include "../../include/linux/libcfs/libcfs.h"
46 #include <linux/module.h>
47 #include <asm/div64.h>
48 
49 #include "../include/obd.h"
50 #include "../include/obd_class.h"
51 #include "../include/lustre_ver.h"
52 #include "../include/obd_support.h"
53 #include "../include/lprocfs_status.h"
54 
55 #include "../include/lustre_req_layout.h"
56 #include "../include/lustre_fld.h"
57 #include "../include/lustre_mdc.h"
58 #include "fld_internal.h"
59 
60 /* TODO: these 3 functions are copies of flow-control code from mdc_lib.c
61  * It should be common thing. The same about mdc RPC lock */
fld_req_avail(struct client_obd * cli,struct mdc_cache_waiter * mcw)62 static int fld_req_avail(struct client_obd *cli, struct mdc_cache_waiter *mcw)
63 {
64 	int rc;
65 
66 	client_obd_list_lock(&cli->cl_loi_list_lock);
67 	rc = list_empty(&mcw->mcw_entry);
68 	client_obd_list_unlock(&cli->cl_loi_list_lock);
69 	return rc;
70 };
71 
fld_enter_request(struct client_obd * cli)72 static void fld_enter_request(struct client_obd *cli)
73 {
74 	struct mdc_cache_waiter mcw;
75 	struct l_wait_info lwi = { 0 };
76 
77 	client_obd_list_lock(&cli->cl_loi_list_lock);
78 	if (cli->cl_r_in_flight >= cli->cl_max_rpcs_in_flight) {
79 		list_add_tail(&mcw.mcw_entry, &cli->cl_cache_waiters);
80 		init_waitqueue_head(&mcw.mcw_waitq);
81 		client_obd_list_unlock(&cli->cl_loi_list_lock);
82 		l_wait_event(mcw.mcw_waitq, fld_req_avail(cli, &mcw), &lwi);
83 	} else {
84 		cli->cl_r_in_flight++;
85 		client_obd_list_unlock(&cli->cl_loi_list_lock);
86 	}
87 }
88 
fld_exit_request(struct client_obd * cli)89 static void fld_exit_request(struct client_obd *cli)
90 {
91 	struct list_head *l, *tmp;
92 	struct mdc_cache_waiter *mcw;
93 
94 	client_obd_list_lock(&cli->cl_loi_list_lock);
95 	cli->cl_r_in_flight--;
96 	list_for_each_safe(l, tmp, &cli->cl_cache_waiters) {
97 
98 		if (cli->cl_r_in_flight >= cli->cl_max_rpcs_in_flight) {
99 			/* No free request slots anymore */
100 			break;
101 		}
102 
103 		mcw = list_entry(l, struct mdc_cache_waiter, mcw_entry);
104 		list_del_init(&mcw->mcw_entry);
105 		cli->cl_r_in_flight++;
106 		wake_up(&mcw->mcw_waitq);
107 	}
108 	client_obd_list_unlock(&cli->cl_loi_list_lock);
109 }
110 
fld_rrb_hash(struct lu_client_fld * fld,u64 seq)111 static int fld_rrb_hash(struct lu_client_fld *fld, u64 seq)
112 {
113 	LASSERT(fld->lcf_count > 0);
114 	return do_div(seq, fld->lcf_count);
115 }
116 
117 static struct lu_fld_target *
fld_rrb_scan(struct lu_client_fld * fld,u64 seq)118 fld_rrb_scan(struct lu_client_fld *fld, u64 seq)
119 {
120 	struct lu_fld_target *target;
121 	int hash;
122 
123 	/* Because almost all of special sequence located in MDT0,
124 	 * it should go to index 0 directly, instead of calculating
125 	 * hash again, and also if other MDTs is not being connected,
126 	 * the fld lookup requests(for seq on MDT0) should not be
127 	 * blocked because of other MDTs */
128 	if (fid_seq_is_norm(seq))
129 		hash = fld_rrb_hash(fld, seq);
130 	else
131 		hash = 0;
132 
133 again:
134 	list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
135 		if (target->ft_idx == hash)
136 			return target;
137 	}
138 
139 	if (hash != 0) {
140 		/* It is possible the remote target(MDT) are not connected to
141 		 * with client yet, so we will refer this to MDT0, which should
142 		 * be connected during mount */
143 		hash = 0;
144 		goto again;
145 	}
146 
147 	CERROR("%s: Can't find target by hash %d (seq %#llx). Targets (%d):\n",
148 		fld->lcf_name, hash, seq, fld->lcf_count);
149 
150 	list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
151 		const char *srv_name = target->ft_srv != NULL  ?
152 			target->ft_srv->lsf_name : "<null>";
153 		const char *exp_name = target->ft_exp != NULL ?
154 			(char *)target->ft_exp->exp_obd->obd_uuid.uuid :
155 			"<null>";
156 
157 		CERROR("  exp: 0x%p (%s), srv: 0x%p (%s), idx: %llu\n",
158 		       target->ft_exp, exp_name, target->ft_srv,
159 		       srv_name, target->ft_idx);
160 	}
161 
162 	/*
163 	 * If target is not found, there is logical error anyway, so here is
164 	 * LBUG() to catch this situation.
165 	 */
166 	LBUG();
167 	return NULL;
168 }
169 
170 struct lu_fld_hash fld_hash[] = {
171 	{
172 		.fh_name = "RRB",
173 		.fh_hash_func = fld_rrb_hash,
174 		.fh_scan_func = fld_rrb_scan
175 	},
176 	{
177 		NULL,
178 	}
179 };
180 
181 static struct lu_fld_target *
fld_client_get_target(struct lu_client_fld * fld,u64 seq)182 fld_client_get_target(struct lu_client_fld *fld, u64 seq)
183 {
184 	struct lu_fld_target *target;
185 
186 	LASSERT(fld->lcf_hash != NULL);
187 
188 	spin_lock(&fld->lcf_lock);
189 	target = fld->lcf_hash->fh_scan_func(fld, seq);
190 	spin_unlock(&fld->lcf_lock);
191 
192 	if (target != NULL) {
193 		CDEBUG(D_INFO, "%s: Found target (idx %llu) by seq %#llx\n",
194 		       fld->lcf_name, target->ft_idx, seq);
195 	}
196 
197 	return target;
198 }
199 
200 /*
201  * Add export to FLD. This is usually done by CMM and LMV as they are main users
202  * of FLD module.
203  */
fld_client_add_target(struct lu_client_fld * fld,struct lu_fld_target * tar)204 int fld_client_add_target(struct lu_client_fld *fld,
205 			  struct lu_fld_target *tar)
206 {
207 	const char *name;
208 	struct lu_fld_target *target, *tmp;
209 
210 	LASSERT(tar != NULL);
211 	name = fld_target_name(tar);
212 	LASSERT(name != NULL);
213 	LASSERT(tar->ft_srv != NULL || tar->ft_exp != NULL);
214 
215 	if (fld->lcf_flags != LUSTRE_FLD_INIT) {
216 		CERROR("%s: Attempt to add target %s (idx %llu) on fly - skip it\n",
217 			fld->lcf_name, name, tar->ft_idx);
218 		return 0;
219 	}
220 	CDEBUG(D_INFO, "%s: Adding target %s (idx %llu)\n",
221 			fld->lcf_name, name, tar->ft_idx);
222 
223 	target = kzalloc(sizeof(*target), GFP_NOFS);
224 	if (!target)
225 		return -ENOMEM;
226 
227 	spin_lock(&fld->lcf_lock);
228 	list_for_each_entry(tmp, &fld->lcf_targets, ft_chain) {
229 		if (tmp->ft_idx == tar->ft_idx) {
230 			spin_unlock(&fld->lcf_lock);
231 			kfree(target);
232 			CERROR("Target %s exists in FLD and known as %s:#%llu\n",
233 			       name, fld_target_name(tmp), tmp->ft_idx);
234 			return -EEXIST;
235 		}
236 	}
237 
238 	target->ft_exp = tar->ft_exp;
239 	if (target->ft_exp != NULL)
240 		class_export_get(target->ft_exp);
241 	target->ft_srv = tar->ft_srv;
242 	target->ft_idx = tar->ft_idx;
243 
244 	list_add_tail(&target->ft_chain,
245 			  &fld->lcf_targets);
246 
247 	fld->lcf_count++;
248 	spin_unlock(&fld->lcf_lock);
249 
250 	return 0;
251 }
252 EXPORT_SYMBOL(fld_client_add_target);
253 
254 /* Remove export from FLD */
fld_client_del_target(struct lu_client_fld * fld,__u64 idx)255 int fld_client_del_target(struct lu_client_fld *fld, __u64 idx)
256 {
257 	struct lu_fld_target *target, *tmp;
258 
259 	spin_lock(&fld->lcf_lock);
260 	list_for_each_entry_safe(target, tmp,
261 				     &fld->lcf_targets, ft_chain) {
262 		if (target->ft_idx == idx) {
263 			fld->lcf_count--;
264 			list_del(&target->ft_chain);
265 			spin_unlock(&fld->lcf_lock);
266 
267 			if (target->ft_exp != NULL)
268 				class_export_put(target->ft_exp);
269 
270 			kfree(target);
271 			return 0;
272 		}
273 	}
274 	spin_unlock(&fld->lcf_lock);
275 	return -ENOENT;
276 }
277 EXPORT_SYMBOL(fld_client_del_target);
278 
279 static struct dentry *fld_debugfs_dir;
280 
fld_client_debugfs_init(struct lu_client_fld * fld)281 static int fld_client_debugfs_init(struct lu_client_fld *fld)
282 {
283 	int rc;
284 
285 	fld->lcf_debugfs_entry = ldebugfs_register(fld->lcf_name,
286 						   fld_debugfs_dir,
287 						   NULL, NULL);
288 
289 	if (IS_ERR_OR_NULL(fld->lcf_debugfs_entry)) {
290 		CERROR("%s: LdebugFS failed in fld-init\n", fld->lcf_name);
291 		rc = fld->lcf_debugfs_entry ? PTR_ERR(fld->lcf_debugfs_entry)
292 					    : -ENOMEM;
293 		fld->lcf_debugfs_entry = NULL;
294 		return rc;
295 	}
296 
297 	rc = ldebugfs_add_vars(fld->lcf_debugfs_entry,
298 			       fld_client_debugfs_list, fld);
299 	if (rc) {
300 		CERROR("%s: Can't init FLD debufs, rc %d\n", fld->lcf_name, rc);
301 		goto out_cleanup;
302 	}
303 
304 	return 0;
305 
306 out_cleanup:
307 	fld_client_debugfs_fini(fld);
308 	return rc;
309 }
310 
fld_client_debugfs_fini(struct lu_client_fld * fld)311 void fld_client_debugfs_fini(struct lu_client_fld *fld)
312 {
313 	if (!IS_ERR_OR_NULL(fld->lcf_debugfs_entry))
314 		ldebugfs_remove(&fld->lcf_debugfs_entry);
315 }
316 EXPORT_SYMBOL(fld_client_debugfs_fini);
317 
hash_is_sane(int hash)318 static inline int hash_is_sane(int hash)
319 {
320 	return (hash >= 0 && hash < ARRAY_SIZE(fld_hash));
321 }
322 
fld_client_init(struct lu_client_fld * fld,const char * prefix,int hash)323 int fld_client_init(struct lu_client_fld *fld,
324 		    const char *prefix, int hash)
325 {
326 	int cache_size, cache_threshold;
327 	int rc;
328 
329 	LASSERT(fld != NULL);
330 
331 	snprintf(fld->lcf_name, sizeof(fld->lcf_name),
332 		 "cli-%s", prefix);
333 
334 	if (!hash_is_sane(hash)) {
335 		CERROR("%s: Wrong hash function %#x\n",
336 		       fld->lcf_name, hash);
337 		return -EINVAL;
338 	}
339 
340 	fld->lcf_count = 0;
341 	spin_lock_init(&fld->lcf_lock);
342 	fld->lcf_hash = &fld_hash[hash];
343 	fld->lcf_flags = LUSTRE_FLD_INIT;
344 	INIT_LIST_HEAD(&fld->lcf_targets);
345 
346 	cache_size = FLD_CLIENT_CACHE_SIZE /
347 		sizeof(struct fld_cache_entry);
348 
349 	cache_threshold = cache_size *
350 		FLD_CLIENT_CACHE_THRESHOLD / 100;
351 
352 	fld->lcf_cache = fld_cache_init(fld->lcf_name,
353 					cache_size, cache_threshold);
354 	if (IS_ERR(fld->lcf_cache)) {
355 		rc = PTR_ERR(fld->lcf_cache);
356 		fld->lcf_cache = NULL;
357 		goto out;
358 	}
359 
360 	rc = fld_client_debugfs_init(fld);
361 	if (rc)
362 		goto out;
363 out:
364 	if (rc)
365 		fld_client_fini(fld);
366 	else
367 		CDEBUG(D_INFO, "%s: Using \"%s\" hash\n",
368 		       fld->lcf_name, fld->lcf_hash->fh_name);
369 	return rc;
370 }
371 EXPORT_SYMBOL(fld_client_init);
372 
fld_client_fini(struct lu_client_fld * fld)373 void fld_client_fini(struct lu_client_fld *fld)
374 {
375 	struct lu_fld_target *target, *tmp;
376 
377 	spin_lock(&fld->lcf_lock);
378 	list_for_each_entry_safe(target, tmp,
379 				     &fld->lcf_targets, ft_chain) {
380 		fld->lcf_count--;
381 		list_del(&target->ft_chain);
382 		if (target->ft_exp != NULL)
383 			class_export_put(target->ft_exp);
384 		kfree(target);
385 	}
386 	spin_unlock(&fld->lcf_lock);
387 
388 	if (fld->lcf_cache != NULL) {
389 		if (!IS_ERR(fld->lcf_cache))
390 			fld_cache_fini(fld->lcf_cache);
391 		fld->lcf_cache = NULL;
392 	}
393 }
394 EXPORT_SYMBOL(fld_client_fini);
395 
fld_client_rpc(struct obd_export * exp,struct lu_seq_range * range,__u32 fld_op)396 int fld_client_rpc(struct obd_export *exp,
397 		   struct lu_seq_range *range, __u32 fld_op)
398 {
399 	struct ptlrpc_request *req;
400 	struct lu_seq_range   *prange;
401 	__u32		 *op;
402 	int		    rc;
403 	struct obd_import     *imp;
404 
405 	LASSERT(exp != NULL);
406 
407 	imp = class_exp2cliimp(exp);
408 	req = ptlrpc_request_alloc_pack(imp, &RQF_FLD_QUERY, LUSTRE_MDS_VERSION,
409 					FLD_QUERY);
410 	if (req == NULL)
411 		return -ENOMEM;
412 
413 	op = req_capsule_client_get(&req->rq_pill, &RMF_FLD_OPC);
414 	*op = fld_op;
415 
416 	prange = req_capsule_client_get(&req->rq_pill, &RMF_FLD_MDFLD);
417 	*prange = *range;
418 
419 	ptlrpc_request_set_replen(req);
420 	req->rq_request_portal = FLD_REQUEST_PORTAL;
421 	req->rq_reply_portal = MDC_REPLY_PORTAL;
422 	ptlrpc_at_set_req_timeout(req);
423 
424 	if (fld_op == FLD_LOOKUP &&
425 	    imp->imp_connect_flags_orig & OBD_CONNECT_MDS_MDS)
426 		req->rq_allow_replay = 1;
427 
428 	if (fld_op != FLD_LOOKUP)
429 		mdc_get_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
430 	fld_enter_request(&exp->exp_obd->u.cli);
431 	rc = ptlrpc_queue_wait(req);
432 	fld_exit_request(&exp->exp_obd->u.cli);
433 	if (fld_op != FLD_LOOKUP)
434 		mdc_put_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
435 	if (rc)
436 		goto out_req;
437 
438 	prange = req_capsule_server_get(&req->rq_pill, &RMF_FLD_MDFLD);
439 	if (prange == NULL) {
440 		rc = -EFAULT;
441 		goto out_req;
442 	}
443 	*range = *prange;
444 out_req:
445 	ptlrpc_req_finished(req);
446 	return rc;
447 }
448 
fld_client_lookup(struct lu_client_fld * fld,u64 seq,u32 * mds,__u32 flags,const struct lu_env * env)449 int fld_client_lookup(struct lu_client_fld *fld, u64 seq, u32 *mds,
450 		      __u32 flags, const struct lu_env *env)
451 {
452 	struct lu_seq_range res = { 0 };
453 	struct lu_fld_target *target;
454 	int rc;
455 
456 	fld->lcf_flags |= LUSTRE_FLD_RUN;
457 
458 	rc = fld_cache_lookup(fld->lcf_cache, seq, &res);
459 	if (rc == 0) {
460 		*mds = res.lsr_index;
461 		return 0;
462 	}
463 
464 	/* Can not find it in the cache */
465 	target = fld_client_get_target(fld, seq);
466 	LASSERT(target != NULL);
467 
468 	CDEBUG(D_INFO, "%s: Lookup fld entry (seq: %#llx) on target %s (idx %llu)\n",
469 			fld->lcf_name, seq, fld_target_name(target), target->ft_idx);
470 
471 	res.lsr_start = seq;
472 	fld_range_set_type(&res, flags);
473 	rc = fld_client_rpc(target->ft_exp, &res, FLD_LOOKUP);
474 
475 	if (rc == 0) {
476 		*mds = res.lsr_index;
477 
478 		fld_cache_insert(fld->lcf_cache, &res);
479 	}
480 	return rc;
481 }
482 EXPORT_SYMBOL(fld_client_lookup);
483 
fld_client_flush(struct lu_client_fld * fld)484 void fld_client_flush(struct lu_client_fld *fld)
485 {
486 	fld_cache_flush(fld->lcf_cache);
487 }
488 EXPORT_SYMBOL(fld_client_flush);
489 
fld_mod_init(void)490 static int __init fld_mod_init(void)
491 {
492 	fld_debugfs_dir = ldebugfs_register(LUSTRE_FLD_NAME,
493 					    debugfs_lustre_root,
494 					    NULL, NULL);
495 	return PTR_ERR_OR_ZERO(fld_debugfs_dir);
496 }
497 
fld_mod_exit(void)498 static void __exit fld_mod_exit(void)
499 {
500 	if (!IS_ERR_OR_NULL(fld_debugfs_dir))
501 		ldebugfs_remove(&fld_debugfs_dir);
502 }
503 
504 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
505 MODULE_DESCRIPTION("Lustre FLD");
506 MODULE_LICENSE("GPL");
507 
508 module_init(fld_mod_init)
509 module_exit(fld_mod_exit)
510